As temperatures drop and the rainy season winds down, Hillsborough County continues mosquito management efforts
As Florida transitions from its hot, rainy summer into cooler months, changes in temperature, rainfall, and humidity can influence mosquito populations across Hillsborough County.
Cooler, drier weather generally creates less favorable conditions for mosquito activity and breeding. However, Florida's subtropical climate allows some mosquitoes to remain active throughout the winter, and even brief periods of rain create new breeding sites around homes and businesses. That makes mosquito prevention especially important as Hillsborough County works to manage mosquito populations and limit the spread of dengue fever, a mosquito-borne illness.
The County continues to rely on aerial and ground treatments, surveillance, and inspections to target mosquitoes at different stages of their life cycles. While seasonal weather can help reduce mosquito activity, residents continue to play an important role in eliminating breeding sites and preventing mosquito bites.
How cooler temperatures affect mosquitoes
Temperatures play a significant role in mosquito development, activity, and survival. During Florida's hot summer months, warm temperatures and frequent rainfall create favorable conditions for mosquitoes to reproduce. As temperatures drop in fall and winter, mosquito activity generally slows, and immature mosquitoes may take longer to develop. Cooler temperatures can also reduce how often some mosquito species seek blood meals, which can limit opportunities for disease transmission. However, the effects vary by species, and mosquitoes do not all respond to temperature changes in the same way.
The Aedes aegypti mosquito, the primary carrier of dengue, is particularly important in Hillsborough County's ongoing response. These mosquitoes live close to people and commonly breed in small containers that collect water around homes, yards, and businesses.
Although cooler weather can make conditions less favorable for Aedes aegypti, it does not guarantee that the mosquitoes will disappear. Florida's relatively mild winters can allow some adults to survive and remain active during warmer periods.
Less rain means fewer opportunities for mosquitoes to breed
Rainfall is another major factor that impacts mosquito populations in Hillsborough County. Florida's rainy season typically provides mosquitoes with abundant opportunities to reproduce. Rainwater collects in every natural depression, including buckets, tires, toys, and other outdoor items. Even small amounts of standing water can support mosquito development.
As the dry season begins, fewer newly formed pools of standing water can mean fewer places for mosquitoes to lay eggs and for larvae to develop. This can help reduce mosquito populations over time. However, less rainfall does not eliminate breeding sites. Sprinklers, irrigation systems, leaking outdoor faucets, clogged gutters, and water left in containers can provide the conditions mosquitoes need to reproduce.
Residents can help prevent new generations of mosquitoes by regularly inspecting their properties and emptying, covering, or removing anything that collects water.
What does low humidity mean for mosquitoes?
Humidity can also influence mosquito activity and survival. Mosquitoes can lose moisture in dry conditions, and low humidity can make it more difficult for some adults to survive, particularly when temperatures are also high. Drier air can contribute to conditions that are less favorable for certain mosquito populations.
However, low humidity does not eliminate mosquitoes on its own. Local conditions matter, including access to shaded resting areas, nearby vegetation, and sources of standing water. Residents should not assume that a stretch of dry weather means their property is free of mosquitoes.
How seasonal weather affects dengue response efforts
Hillsborough County continues to respond to an outbreak of dengue fever, with mosquito surveillance used to identify virus activity in mosquito populations in affected neighborhoods. The County has increased both aerial and ground mosquito management operations with the help of local, state, and federal partners.
Winter can help reduce mosquito populations in Hillsborough County, but it's unlikely to eliminate them completely. Sustained cooler temperatures can slow mosquito development, reduce activity, and make survival more difficult. However, aerial and ground treatments remain critical to addressing the public health concern. It's also important for residents to remain vigilant. Hillsborough County Mosquito Management reminds residents to protect themselves from mosquito bites following the 3 Ds:
- Dress: Wear light-colored, long-sleeved clothing and closed-toed shoes.
- Defend: Use an insect repellent containing a CDC-recommended ingredient, such as DEET or Picaridin.
- Dump: Dump or cover standing water around your home. Mosquitoes that spread dengue commonly breed in small containers that hold water.
Residents are encouraged to visit the County's mosquito operations hub. There, residents can sign up to receive notifications about localized aerial treatments, report mosquito issues, and stay up to date on latest updates surrounding the dengue virus.
Hillsborough County services are paid for in part by property taxes. Learn more at HCFL.gov/PropertyTax.